Device and method for measuring battery current

Abstract

The invention discloses a battery current measuring device and method. The battery current measuring device includes: a first sensor portion connected to a battery and measuring a current; a second sensor portion connected to the first sensor portion and measuring a current; a switching portion connected to the second sensor portion and switching connection of the second sensor portion; and a processor that calculates a current of the battery based on a first current value of the first sensor portion and a second current value of the second sensor portion, calculates a state of charge (SOC) of the battery corresponding thereto, and compares the first current value with the second current value to detect a defective current sensor among the plurality of current sensors. The battery current measuring apparatus and method can reduce heat generation and measurement errors associated with temperature through current distribution even at an upper limit current, can improve accuracy of current measurement, can easily detect a fault of a current sensor, and can easily distinguish defective current sensors.

Description

Technical Field

[0001] The present invention relates to a battery current measuring device connected to a battery to measure the current of the battery and detect a failure of a current sensor and a battery current measuring method thereof. Background Art

[0002] In recent years, the application of batteries has expanded not only to mobile devices such as mobile phones, tablet computers, etc., but also to electric vehicles (EV, HEV, PHEV), energy storage systems (ESS), etc.

[0003] The battery generates heat when being charged and discharged, and a current sensor for measuring the charge and discharge current of the battery is disposed near the battery cell and is therefore affected by the heat generated by the battery cell, resulting in increased measurement errors or malfunctions.

[0004] Therefore, there is a growing interest in accurately measuring the charge and discharge current of a battery and detecting failures of the current sensors.

[0005] Typically, the measurement of the battery current is performed by a single sensor covering the entire current range or by several sensors each covering a portion of the entire current range. Additionally, such current measurement methods may employ interpolation of a line connecting two points.

[0006] However, such a current measurement method has a problem in that the measurement accuracy is not uniform over the entire current measurement area.

[0007] Furthermore, in this current measurement method, the current sensor may generate heat when measuring a high current, thereby causing degradation in measurement accuracy through an increase in internal resistance.

[0008] If a certain current sensor has failed, the battery cannot distinguish the defective current sensor from a normal current sensor, and all current sensors need to be replaced or the measurement values ​​need to be checked one by one.

[0009] The background art of the present invention is disclosed in Korean Patent Publication No. 10-2021-0104457 (titled “Battery Device and Current Sensor Diagnostic Method”) and the like. Summary of the invention

[0010] One aspect of the present invention provides a battery current measurement device and method, which can minimize heat generation and resistance increase through a current sensor while improving the accuracy of current measurement through current distribution.

[0011] According to one aspect of the present invention, a battery current measuring device includes: a first sensor part, which is connected to a battery and measures current; a second sensor part, which is connected to the first sensor part and measures current; a switch part, which is connected to the second sensor part and switches the connection of the second sensor part; and a processor, which calculates the current of the battery based on a first current value of the first sensor part and a second current value of the second sensor part, calculates the state of charge (SOC) of the battery corresponding thereto, and compares the first current value with the second current value to detect a defective current sensor among a plurality of current sensors included in the first sensor part and the second sensor part.

[0012] When it is determined that the first current value and the second current value are the same within the tolerance, the processor can determine that the first sensor part and the second sensor part are operating normally, and when it is determined that the first current value and the second current value are different, the processor can determine that either one of the first sensor part and the second sensor part has failed.

[0013] The second sensor part may include a third current sensor, a fourth current sensor, and a fifth current sensor connected in parallel to each other, and the processor may calculate the second current value by summing current values ​​measured by the third to fifth current sensors.

[0014] When the first current value is different from the second current value, the processor can compare the third current value of the third current sensor, the fourth current value of the fourth current sensor, and the fifth current value of the fifth current sensor to determine that the current sensor corresponding to the current value outside the preset range is a defective current sensor.

[0015] The switching part may include: a first switch, which is connected in series to the third current sensor; a second switch, which is connected in series to the fourth current sensor; and a third switch, which is connected in series to the fifth current sensor, and any one of the first to third switches can be turned on or off in response to a control signal from the processor.

[0016] When the first current value and the second current value are different, the processor can control the first switch to the third switch to be turned off sequentially, and can calculate the second current value based on the current values ​​of two current sensors among the multiple current sensors of the second sensor part in response to the operation of the switch part to detect a defective current sensor by comparing the second current value with the first current value.

[0017] Upon determining that the third to fifth current sensors are operating normally, the processor may determine that the first current sensor of the first sensor part has failed.

[0018] The processor may turn off a switch connected to the defective current sensor among the first to third switches to disconnect the defective current sensor.

[0019] According to another aspect of the present invention, a battery current measurement method includes: measuring current by a first sensor part connected to a battery; measuring current by a second sensor part connected to the first sensor part; detecting a defective current sensor among a plurality of current sensors included in the first sensor part and the second sensor part by comparing a first current value of the first sensor part with a second current value of the second sensor part by a processor; controlling a switch part by the processor to disconnect the defective current sensor; and calculating the current of the battery based on the first current value and the second current value by the processor, and then calculating the state of charge (SOC) of the battery corresponding thereto.

[0020] In the step of measuring the current by the second sensor part connected to the first sensor part, the processor may calculate the second current value by summing current values ​​measured by third to fifth current sensors included in the second sensor part and connected in parallel to each other.

[0021] The step of detecting a defective current sensor may include: comparing, by a processor, a first current value with a second current value; determining, by the processor, that the first sensor part and the second sensor part are operating normally when the first current value and the second current value are the same within a tolerance; and determining, by the processor, that any one of the current sensors included in the first sensor part and the second sensor part is a defective current sensor when the first current value and the second current value are different.

[0022] The detecting of the defective current sensor may further include determining that the corresponding current sensor is a defective current sensor when any one of current values ​​input from the third to fifth current sensors of the second sensor part is outside a preset range.

[0023] The step of detecting a defective current sensor may also include: sequentially turning off the first switch to the third switch included in the switch part to disconnect the current sensor connected to each switch; comparing the second current value and the first current value by calculating the second current value based on the current values ​​measured by two current sensors normally connected; when the first current value and the second current value are different, controlling the next switch; and when the first current value and the second current value are the same, determining by the processor that the disconnected current sensor is a defective current sensor.

[0024] The step of detecting the defective current sensor may further include determining that the first current sensor of the first sensor part is the defective current sensor when it is determined that all current sensors of the second sensor part are operating normally.

[0025] The step of disconnecting the defective current sensor may further include turning off a switch connected to the defective current sensor among first to third switches included in the switch part to disconnect the defective current sensor.

[0026] According to one aspect of the present invention, a battery current measurement apparatus and method can reduce heating and temperature-related measurement errors through current distribution even at high limiting currents.

[0027] According to one aspect of the present invention, a battery current measurement device and method can improve the accuracy of current measurement.

[0028] According to an aspect of the present invention, a battery current measuring device and method can easily detect a failure of a current sensor and can easily distinguish a defective current sensor using a plurality of current sensors connected in parallel to each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a block diagram of a battery pack including a current measuring device according to one embodiment of the present invention.

[0030] Figure 2 is a diagram showing a connection configuration of a battery pack including a current measuring device according to an embodiment of the present invention.

[0031] Figure 3 is a diagram showing a configuration of a current measuring device according to an embodiment of the present invention.

[0032] Figure 4 is a flow chart illustrating a battery current measurement and fault detection method of a current measurement device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The drawings may be exaggerated in width, length, and thickness of parts only for the convenience and clarity of description. In addition, the terms used herein are defined by considering the functions of the present invention and may be changed according to the customization or intention of the user or operator. Therefore, the definition of terms should be made according to the overall disclosure set forth herein.

[0034] Figure 1 is a block diagram of a battery pack including a current measuring device according to one embodiment of the present invention.

[0035] refer to Figure 1 The current measuring device is connected to the battery 190 to be included in the battery pack 100 , and includes a first sensor part 140 , a second sensor part 150 , a switch part 160 , and a processor 110 .

[0036] The battery 190 may be charged by the supplied charging current and may output the charging current. The battery 190 may include a plurality of battery cells.

[0037] The first sensor part 140 is connected to the battery 190 to sense a current output from the battery 190 and apply the sensed current to the processor 110. The first sensor part 140 may include at least one current sensor.

[0038] The second sensor part 150 is connected to the first sensor part 140 to sense the current of the battery 190. The second sensor part 150 may include a plurality of current sensors.

[0039] The switch part 160 is connected to the second sensor part 150 to switch the connection of the second sensor part 150. The switch part 160 switches the connection of at least one of the plurality of current sensors included in the second sensor part 150 in response to a control signal from the processor 110.

[0040] The processor 110 calculates a state of charge (SOC) of the battery 190 based on the current value input from the first sensor part 140 and the second sensor part 150 .

[0041] The processor 110 may be a battery management system (BMS) or a main control unit (MCU). The processor 110 may include a memory or a buffer.

[0042] The processor 110 can detect a fault of the current sensor by comparing the current values ​​of the first sensor part 140 and the second sensor part 150. The processor 110 can detect a fault of the current sensor by comparing a first current value of the first sensor part 140 with a second current value of the second sensor part 150 and determining whether the two current values ​​are the same.

[0043] When determining that any one of the current sensors has failed, the processor 110 controls the switch part 160 to detect the defective current sensor. The processor 110 sends a control signal to the switch part 160 to disconnect the defective current sensor.

[0044] By disconnecting the defective current sensor, processor 110 allows current to be measured without the defective current sensor.

[0045] Processor 110 may generate an alarm when at least one current sensor fails.

[0046] Therefore, the current measuring device can measure the correct current of the battery 190 through the normal current sensor by excluding the defective current sensor.

[0047] Figure 2 is a diagram showing a connection configuration of a battery pack including a current measuring device according to an embodiment of the present invention.

[0048] refer to Figure 2 The current measuring device includes a first terminal 11 connected to the cathode of the battery 190 and a second terminal 12 connected to the anode of the battery 190. In addition, the current measuring device includes a third terminal 21 connected to the first terminal 11 and a fourth terminal 22 connected to the second terminal 12.

[0049] The first terminal 11 is connected to the third terminal 21 through the first DC connector 181 and the first micro switch 171 .

[0050] The second terminal 12 is connected to the first sensor part 140, the second sensor part 150 and the switch part 160. In addition, the second terminal 12 is connected to the fourth terminal 22 through the second micro switch (micro SW) 172 and the second connector (DC connector) 182 connected to the switch part 160.

[0051] The first sensor part 140 is connected to the second terminal 12 at one end thereof, and is connected to the second sensor part 150 at the other end thereof. The second sensor part 150 is connected to the first sensor part 140 in series.

[0052] The switch portion 160 may be connected to the second sensor part 150 in series.

[0053] The switch part 160 may include a plurality of switches respectively connected in series to a plurality of current sensors included in the second sensor portion 150 .

[0054] The processor 110 may operate in any one of the charging mode and the discharging mode by controlling the first connector 181 , the second connector 182 , the first micro switch 171 , and the second micro switch 172 in response to charging of the battery 190 or outputting a discharging current from the battery 190 .

[0055] The processor 110 may be connected to the first sensor part 140 and the second sensor part 150 to control the switch part 160 depending on the measured current value.

[0056] In the event that any one of the plurality of current sensors included in the first sensor part 140 and the second sensor part 150 fails, the processor 110 may interrupt the charging mode or the discharging mode of the battery 190 to establish the test mode.

[0057] The processor 110 controls the switch part 160 to detect and disconnect the defective current sensor depending on the measured current value, and controls the current sensor to operate in the charging mode or the discharging mode again.

[0058] Figure 3 is a diagram showing a configuration of a current measuring device according to an embodiment of the present invention.

[0059] like Figure 3 As shown, the current measuring device measures the current of the battery 190 and detects a malfunction of the current sensor.

[0060] The first sensor part 140 may include a first current sensor 141 .

[0061] In some embodiments, the first sensor portion 140 may further include a second current sensor (not shown). The second current sensor may be connected in parallel with the first current sensor 141 .

[0062] The first current sensor 141 is connected to the processor 110 at both ends S11 , S12 thereof to apply a first current value to the processor 110 .

[0063] The second sensor part 150 may be connected to the first current sensor 141 in series.

[0064] The second sensor part 150 may include a third current sensor 151, a fourth current sensor 152, and a fifth current sensor 153. In some embodiments, the second sensor part 150 may further include a sixth current sensor (not shown).

[0065] The third to fifth current sensors 151 to 153 may be connected in parallel to each other.

[0066] The third current sensor 151 is connected to the processor 110 at both ends S21 , S22 thereof to apply a third current value to the processor 110 .

[0067] The fourth current sensor 152 is connected to the processor 110 at both ends S31 , S32 thereof to apply a fourth current value to the processor 110 .

[0068] The fifth current sensor 153 is connected to the processor 110 at both ends S41 , S42 thereof to apply a fifth current value to the processor 110 .

[0069] The processor 110 may sum the third current value, the fourth current value, and the fifth current value to calculate the second current value.

[0070] The switch part 160 includes a plurality of switches respectively connected in series to the current sensors of the second sensor part 150 .

[0071] The switch part 160 may include a first switch 161 , a second switch 162 , and a third switch 163 .

[0072] The first to third switches 161 to 163 may be connected in parallel to each other.

[0073] When the second sensor unit 150 further includes a sixth current sensor, the switch part 160 may further include a fourth switch connected to the sixth current sensor.

[0074] The first switch 161 is connected in series to the third current sensor 151 to connect or disconnect the third current sensor 151 .

[0075] The second switch 162 is connected in series to the fourth current sensor 152 to connect or disconnect the fourth current sensor 152 .

[0076] The third switch 163 is connected in series to the fifth current sensor 153 to connect or disconnect the fifth current sensor 153 .

[0077] In the switching part 160 , the first to third switches 161 to 163 may be turned on or off in response to a control signal CS1 from the processor 110 .

[0078] The processor 110 compares the first current value measured by the first current sensor 141 with a second current value which is the sum of the current values ​​measured by the third to fifth current sensors 151 to 153 .

[0079] When the first current value and the second current value are identical within the tolerance, the processor 110 determines that all of the first current sensor 141 and the third to fifth current sensors 151 to 153 are operating normally.

[0080] Here, the processor 110 transmits the control signal CS1 to allow the first to third switches 161 to 163 to remain in the on state.

[0081] On the other hand, when there is a difference of a certain value or more between the first current value and the second current value, the processor 110 may determine that one of the current sensors has failed.

[0082] Here, the processor 110 may compare the respective current values ​​of the third to fifth current sensors 151 to 153 to determine a defective current sensor.

[0083] The processor 110 determines whether the third current value, the fourth current value, and the fifth current value are within a preset range.

[0084] When at least one of the third current value, the fourth current value, and the fifth current value is different or outside a preset range, the processor 110 may detect the current sensor providing the corresponding current value as a defective current sensor.

[0085] In addition, the processor 110 may control a plurality of switches in the switching part 160 to detect a defective current sensor.

[0086] The processor 110 may sequentially turn off the first switch 161 and the third switch 163 to detect a defective current sensor by summing the two current values.

[0087] The processor 110 sequentially controls any one of the first to third switches 161 to 163 of the switch part 160 to be turned off.

[0088] When the first switch 161 is turned off, the processor 110 compares the first current value measured by the first current sensor 141 with a second current value which is the sum of the current values ​​measured by the fourth current sensor 152 and the fifth current sensor 153 .

[0089] When the first current value and the second current value are the same, the processor 110 may determine that the third current sensor 151 has failed.

[0090] On the other hand, when the first current value and the second current value are different, the processor 110 controls the switching part 160 again.

[0091] The processor 110 may send a control signal to allow the first switch 161 to be turned on and the second switch 162 to be turned off.

[0092] When the fourth current sensor 152 is turned off by the second switch 162 , the processor 110 compares the first current value measured by the first current sensor 141 with a second current value which is the sum of the current values ​​measured by the third current sensor 151 and the fifth current sensor 153 .

[0093] When the first current value and the second current value are the same, the processor 110 may determine that the fourth current sensor 152 is a defective current sensor.

[0094] When the first current value and the second current value are different, the processor 110 may control the third switch 163 .

[0095] In the case where the fifth current sensor 153 is disconnected, the processor 110 may detect a defective current sensor by comparing the first current value with the second current value.

[0096] When all current sensors of the second sensor part 150 operate normally, the processor 110 may determine that the first current sensor 141 has failed.

[0097] The processor 110 may transmit a control signal CS1 to the switching part 160 to turn off a switch connected to the defective current sensor.

[0098] As a result, when a defective current sensor is disconnected, the current measuring device can easily detect and exclude the defective current sensor, thereby improving the measurement accuracy.

[0099] In addition, the processor 110 may calculate a state of charge (SOC) of the battery 190 based on current values ​​of the first sensor part 140 and the second sensor part 150 that are normally operated.

[0100] The first sensor part 140 may further include a second current sensor connected in parallel to the first current sensor 141 and a switch connected thereto to detect a defective current sensor by sequentially controlling the switch to be turned on or off.

[0101] In addition, as described above, the processor 110 may detect a malfunction of the current sensor based on a result of comparing the first current value with the second current value.

[0102] The processor 110 is connected to the second terminal 12 to receive the current value measured by the first sensor part 140 and the second sensor part 150 to determine the state of charge (SOC) of the battery 190 .

[0103] The processor 110 determines a current value of the battery 190 based on the first current value of the first sensor part 140 and the second current value of the second sensor part 150 .

[0104] In addition, the processor 110 may detect a failure of a specific current sensor included in the first sensor part 140 and the second sensor part 150 based on the first current value of the first sensor part 140 and the second current value of the second sensor part 150 .

[0105] Figure 4 is a flow chart illustrating a battery current measurement and fault detection method of a current measurement device according to an embodiment of the present invention.

[0106] refer to Figure 4 , the current measuring device determines the state of the battery 190 and detects a defective current sensor.

[0107] The first sensor part 140 senses a first current value through the first current sensor 141 and applies the first current value to the processor 110 (S310).

[0108] The processor 110 receives a first current value from the first current sensor 141 of the first sensor part 140 .

[0109] The second sensor part 150 senses current values ​​passing through the third to fifth current sensors 151 to 153 and applies the current values ​​to the processor 110 ( S320 ).

[0110] The third current sensor 151 may measure a third current value, the fourth current sensor 152 may measure a fourth current value, and the fifth current sensor 153 may measure a fifth current value.

[0111] The processor 110 may compare the measured current with the reference current (S330). Then, when the measured current is less than the reference current, the processor 110 controls the switch part 160 (S340) and turns off one of the switches to disconnect any one current sensor (nth current sensor) in the second sensor part 150 (S350).

[0112] Since the magnitude of the current is small, the processor 110 may allow only a few current sensors to measure the current.

[0113] The processor 110 calculates a second current value which is the sum of the current values ​​of the second sensor part 150 (S360).

[0114] The processor 110 calculates the second current value by summing the current values ​​of the third to fifth current sensors 151 to 153 of the second sensor part 150 .

[0115] The processor 110 compares the first current value with the second current value ( S370 ).

[0116] When the first current value and the second current value are identical within the tolerance, the processor 110 determines that the plurality of current sensors included in the first sensor part 140 and the second sensor part 150 are operating normally.

[0117] Furthermore, when the first current value of the first sensor part 140 and the second current value of the second sensor part 150 are different, the processor 110 determines that any one of the current sensors has failed (S380).

[0118] The processor 110 checks the magnitudes of the third to fifth current values ​​of the third to fifth current sensors 151 to 153 of the second sensor part 150 and detects a current value outside a preset range.

[0119] The processor 110 may determine that the current sensor corresponding to the current value outside the preset range has failed. The processor 110 may sequentially disconnect any one of the third to fifth current sensors 151 to 153 of the second sensor part 150 by sequentially turning off the first to third switches 161 to 163 (S390).

[0120] The processor 110 may compare the sum of the current values ​​of the two current sensors with the first current value, and may detect a defective current sensor based on the comparison result.

[0121] When all current sensors of the second sensor part 150 operate normally, the processor 110 may determine that the first current sensor 141 has failed.

[0122] When a defective current sensor is detected, the processor 110 controls a switch connected to the defective current sensor to be turned off.

[0123] The switching part 160 turns off the Nth switch in response to the control signal.

[0124] Therefore, when the switch connected to the defective current sensor is turned off, the defective current sensor is turned off (S400).

[0125] After disconnecting the defective current sensor, the processor 110 calculates the current of the battery 190 and the state of charge (SOC) of the battery 190 corresponding to the first current value and the second current value (S410).

[0126] The processor 110 may generate and externally transmit an alarm regarding the presence of a defective current sensor. On the other hand, when the first current sensor has failed, the processor 110 may shut down the operation of the current measuring device.

[0127] Therefore, the battery current measuring device and method according to the present invention can easily detect and disconnect a defective current sensor to accurately calculate the current and charging state of the battery. In addition, the battery current measuring device and method according to the present invention can measure high current by distributing the high current through multiple current sensors.

[0128] Although the present invention has been described with reference to some exemplary embodiments, it will be appreciated by those skilled in the art that these embodiments are given by way of illustration only, and that various modifications, variations and alterations may be made without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention shall be limited only by the appended claims and their equivalents.

Claims

1. A battery current measuring device, comprising: a first sensor portion, connected to the battery and measuring the current; a second sensor portion connected to the first sensor portion and measuring current; a switch part connected to the second sensor part and switching connection of the second sensor part; as well as A processor calculates the current of the battery based on a first current value of the first sensor part and a second current value of the second sensor part, calculates a state of charge SOC of the battery corresponding to the first current value and the second current value, and compares the first current value with the second current value to detect a defective current sensor among a plurality of current sensors included in the first sensor part and the second sensor part.

2. The battery current measuring device according to claim 1, wherein: When determining that the first current value and the second current value are the same within a tolerance, the processor determines that the first sensor part and the second sensor part are operating normally, and when determining that the first current value and the second current value are different, the processor determines that either one of the first sensor part and the second sensor part has failed.

3. The battery current measuring device according to claim 1, wherein: The second sensor section includes a third current sensor, a fourth current sensor, and a fifth current sensor connected in parallel to each other, and the processor calculates the second current value by summing current values ​​measured by the third to fifth current sensors.

4. The battery current measuring device according to claim 3, wherein: When the first current value and the second current value are different, the processor compares the third current value of the third current sensor, the fourth current value of the fourth current sensor, and the fifth current value of the fifth current sensor to determine that the current sensor corresponding to the current value outside the preset range is the defective current sensor.

5. The battery current measuring device according to claim 3, wherein: The switch part comprises: a first switch connected in series to the third current sensor; a second switch connected in series to the fourth current sensor; and a third switch, connected in series to the fifth current sensor, Any one of the first to third switches is turned on or off in response to a control signal from the processor.

6. The battery current measuring device according to claim 5, wherein: When the first current value and the second current value are different, the processor controls the first to third switches to be turned off sequentially, and in response to the switch part detecting the operation of the defective current sensor by comparing the second current value with the first current value, calculates the second current value based on the current values ​​of two current sensors among the multiple current sensors of the second sensor part.

7. The battery current measuring device according to claim 6, wherein: Upon determining that the third to fifth current sensors are operating normally, the processor determines that the first current sensor of the first sensor portion has failed.

8. The battery current measuring device according to claim 5, wherein: The processor turns off a switch connected to the defective current sensor among the first to third switches to disconnect the defective current sensor.

9. A battery current measurement method, comprising: measuring the current by a first sensor portion connected to the battery; measuring current by a second sensor portion connected to the first sensor portion; detecting, by the processor, a defective current sensor among a plurality of current sensors included in the first sensor part and the second sensor part by comparing a first current value of the first sensor part with a second current value of the second sensor part; controlling the switch portion by the processor to disconnect the defective current sensor; as well as The processor calculates the current of the battery based on the first current value and the second current value, and then calculates the state of charge SOC of the battery corresponding to the first current value and the second current value.

10. The battery current measurement method according to claim 9, wherein: In the step of measuring the current by the second sensor part connected to the first sensor part, the processor calculates the second current value by summing current values ​​measured by third to fifth current sensors included in the second sensor part and connected in parallel to each other.

11. The battery current measurement method according to claim 9, wherein: The steps to detect a defective current sensor include: comparing, by the processor, the first current value with the second current value; determining, by the processor, that the first sensor portion and the second sensor portion are operating normally when the first current value and the second current value are the same within a tolerance; and When the first current value and the second current value are different, it is determined by the processor that any one of the current sensors included in the first sensor part and the second sensor part is the defective current sensor.

12. The battery current measurement method according to claim 11, wherein: The step of detecting the defective current sensor further includes: when any one of the current values ​​input from the third current sensor to the fifth current sensor of the second sensor part is outside a preset range, determining that the corresponding current sensor is the defective current sensor.

13. The battery current measurement method according to claim 11, wherein: The steps of detecting a defective current sensor also include: sequentially turning off first to third switches included in the switch part to disconnect a current sensor connected to each switch; comparing the second current value with the first current value by calculating the second current value from current values ​​measured by two current sensors that are normally connected; When the first current value and the second current value are different, controlling a next switch; and When the first current value and the second current value are the same, it is determined by the processor that the disconnected current sensor is the defective current sensor.

14. The battery current measurement method according to claim 11, wherein: The step of detecting the defective current sensor further includes determining that the first current sensor of the first sensor part is the defective current sensor when it is determined that the plurality of current sensors of the second sensor part are operating normally.

15. The battery current measurement method according to claim 9, wherein: The step of disconnecting the defective current sensor further includes turning off a switch connected to the defective current sensor among first to third switches included in the switch part to disconnect the defective current sensor.

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